Welding....

[KILLA]

i dont want anyone to think im an idiot, but im still skeptical about welding my cams. i already have someone who will do it for free provided i get it ready for him ( and yes, he is a highly experienced engineer and welder). But when we got in there to tack it all up, he really began making some good points. which leads me to one question.
Could the cause of the slippage be due to the hydraulic tensioner for the timing chain. Not the main chain but the two smaller ones on eaither side that keep the two cams for each head in time.
Upon inspection of the hydraulic cylinder that regulates this tension, i found that the hole for the fluid to enter is literally the size of a pinhole. because its at the highest point in the engine, it gets less pressure as it is. so low oil, or even the smallest particle blocking the hole even slightly, would result in a loosened chain. which would cause the exact problem these cars are experiencing.
Another thing. who has the highest mileage on their welds so far. because wether you do the weld right or not, the temper in the metal will be significantly changed, causing the cam to be overly soft or overly brittle.

In conclusion, since no one knows the root cause of this problem. Perhaps it could be corrected with a less drastic procedure. anyone dare to not weld their cams and put in a high pressure oil pump and/or dual oil filters to prevent uneven loads on the failing sprocket.

Im not so opinionated as to think this has to be the problem, im just exploring all the possibilities before i actually make my choice.

 

[nothingtoseehere]

I have 165XXX on my Kirked SHO.

The "test" you are thinking of is awfully risky. Have you tried to price a new motor for a gen III. I am sure Chris can/will elaborate on the issues you mentioned.

 

[V6&V8SHO]

Actually the cause has been proven. Have you actually seen a failed cam? I have over at E1's house. After you see one of these, you will get welded.

 

[KILLA]

Actually the cause has been proven. Have you actually seen a failed cam? I have over at E1's house. After you see one of these, you will get welded.

If it has already been proven then what is? From what i can tell, everybody is making the same educated guess. If it is the sprocket itself, then they obviously didnt design the cam to tolerate the forces being applied to it. So, is there any kind of replacement sprocket & chain sets. perhaps a double thick chain w/ two sprokets per cam to distribute loads properly.

ahh f*** it... i dont even know why im bothering. Im just going to weld it and be done with it. I would rather it have a small if not 0% chance of failure than almost certain. However, i would like to continue this dicussion unless no one cares.

 

[HoustinoJillian]

http://www.v8sho.com/SHO/StillskepticalaboutCamWelding.htm

 

[Porkchop]

If it has already been proven then what is? From what i can tell, everybody is making the same educated guess. If it is the sprocket itself, then they obviously didnt design the cam to tolerate the forces being applied to it. So, is there any kind of replacement sprocket & chain sets. perhaps a double thick chain w/ two sprokets per cam to distribute loads properly.

What your implying as a fix sounds good, but remember... these motors have 0 aftermarket except for what has been developed. Deveolping something like this is difficult and pricey and not everyone has the access to the skills, tools or materials needed to make such a thing. Besides, changing the alternator is a ***** by itself, changing the entire timing set over would be 10x worse.

Its been proven that while expensive, welding is the ONLY way to fix this issue, except getting out of SHO's all together. When I found out that my rear exhaust cam was moving my heart sunk to the floor, thank god it was at Kirks shop getting ready to be welded at the time. Now, I don't have any second thoughts about driving the car.

 

[ArkanSHO]

The reason for the failure is a combination of issues. Examination of a failed camsprocket it becomes obvious what the results are from. The simple explenation is that the two sprockets are not in exact line with each other when under BOTH exeleration and decleration which cause quite different loads on the spocket other then the planned rotational torque load. The net loading causes the sprockets to pull to the in opposite directions during each rotation. The result will be the weakest link in the connection will give way. That link on most multi-cammed engines is the chain of the teeth on the sprocket. On ours there is non-fused joint that is forced into articulation with each rotation. I am of the opinion that pinning may not be the best resolution as the pin acts as an axis for the articulating joint causing wear on the point of jointing which will result in the pin being flung out if is not welded to the sprocket. The axial movement of pin will still cause wear on the the camshaft tube.

 

[KILLA]

Cool. Looks like youve done just about everything to the genIII. i would be stupid not to take your word for it. How many miles you got on those welds anyway, and did you do it yourself?

 

[spragers]

I only have about 10k miles on my welds, but they've been fine for 3 1/2 years now.

 

[ArkanSHO]

Cool. Looks like youve done just about everything to the genIII. i would be stupid not to take your word for it. How many miles you got on those welds anyway, and did you do it yourself?

I had a machine shop do the welds about 65,000 miles ago on mine. 60,000 of those miles have been under boost.

 

[Ian Macoomb]

I've got over 50,000 miles on my welds and about 128k miles on the car. It's obviously a design flaw. You're best off welding them and forgetting about it, then start worrying about the tranny and coils.

 

[E1]

I hit a concrete barrier at highway speeds and punched 3 holes in the Block. The Welds Held....

 

[ArkanSHO]

Yeah, but is that the recommended test for the camshaft sprocket welds? Guess you have to improvise when you don't have X-ray equipment available, eh?

 

[MotorMouth]

Yeah, but is that the recommended test for the camshaft sprocket welds? Guess you have to improvise when you don't have X-ray equipment available, eh?

For saftey sake of all involved I don't believe that that should be a reccomended component durability testing procedure.

 

[RAYJAY]

I hit a concrete barrier at highway speeds and punched 3 holes in the Block. The Welds Held....

you have a 96 rose mist .......


pictures please :corn: